1. Field of the Invention
This invention relates in general to a cover for a spoked wheel and more particularly to a method and device of attaching and tensioning a flexible cover on a spoked wheel.
2. Background of the Invention
Spoked wheels are extrememly lightweight for their strength. This feature is very advantageous on bicycles, particularly touring or racing bicycles, where it is desirable to obtain as light a weight as possible to obtain low road friction and to decrease inertia. A spoked bicycle wheel may be as light as two pounds or less.
Spokes, however, cause considerable aerodynamic drag which must be overcome by the motive force, such as a motor or pedeler. The amount of drag increases approximately with the square of the speed, so drag is of particular importance on high-speed racing bikes, but it is present to some degree at all speeds and results in wasted energy.
One method to overcome spoke drag is elimination of the spokes and substitution of solid rim. However, these solid rims have several drawbacks. Even though they may be constructed of materials using the latest technology, solid rims are heavier then spoked wheels. Therefore, they increase the road friction, and the high inertia contributes to slow start-up speeds and more difficult stopping. These wheels are currently extremely expensive and may cost as high as $1,000.00 per wheel. The solid wheels weigh approximately 4 pounds.
Therefore, it is desirable to have a lightweight cover for a spoked wheel.
There are several problems associated with devising a spoked wheel cover. A major problem is that rims of spoked wheels flex in the axial direction. Spoked bicycle rims typically flex about 1/2 inch in each direction. Therefore, a wheel cover must flex or otherwise be mounted to account for this flexion. If a flexible cover is used to satisfy the above criterion, then it is usually difficult to attach and be secured to the wheel. Additionally, if thin, lightweight, flexible material is used to cover the wheel, besides having to attach it, it is necessary to tension it to provide a smooth, low-drag configuration.
Therefore, it is desirable to have a flexible, lightweight wheel cover for a spoked wheel.
It is desirable that such a wheel cover be easily attachable to conventional spoked wheels, without modification to the wheel.
It is further desirable that such a wheel cover be attractive in appearance, be easily and quickly installed, and be of low cost.